Many scholars have speculated as to the origins and age of each concerto: there is a case for dating the sixth concerto to the earliest stage of the composition. The BBC work page for Brandenburg Concerto No 6 in B flat major, BWV by Johann Sebastian Bach. Find upcoming concerts, watch. Bach, Johann Sebastian / BRANDENBURG CONCERTO NO. 6 IN B-FLAT MAJOR, BWV - Score and Parts. ID: Document Image. View Score.